I prefer the TOS
Klingons in pretty much every way. The TOS
characterization is more interesting to me than the space samurai angle that TNG
adopted, and while I like the TNG
makeup, I would have preferred it to have been used for a different species. I have no problem at all with the TOS
Klingon makeup, though I'll admit that I prefer when they at least went to the trouble of adding bushy eyebrows.
The "look" and characterization of TNG
Klingons is different enough from those of TOS
Klingons that that but for the cultural cache of the term "Klingon," they might as well have been separate species.
movie appearances kind of splits the difference, with the new look but characterization that fits in fine with the series. Well, kinda the new look. Mark Lenard's Klingon commander at the beginning of TMP
doesn't really look like either makeup scheme, and there are a few Klingons here and there throughout the film series that look more like Lenard's character than they do the TNG